Is it possible to have shadowed password file without implementing a Trusted System?
Yes...
You need to install ShadowPW B.01.00.00 HP-UX 11.11 Shadow Password Enablement Product
Is this Product available with the OS installation CD?
Download here:
Hewlett-Packard Co.
RPoduct and installation notes:
http://docs.hp.com/en/5991-0909/5991-0909.pdf